Organic pollution is a significant challenge in environmental protection, especially the discharge of refractory organic pollutants in chemical production and domestic use. The biological treatment method of traditional sewage treatment plants cannot degrade such pollutants, which leads to the continuous transfer of these pollutants into the water environment. Therefore, it is necessary to study clean and efficient advanced treatment technologies to degrade organic pollutants. The ozone/UV advanced oxidation process (O3/UV) has attracted extensive attention. This paper summarizes the reaction mechanism of O3/UV and analyzes its application progress in industrial wastewater, trace polluted organic matter and drinking water. The existing research results show that this technology has an excellent performance in the degradation of organic pollutants and has the characteristics of clean and environmental protection. In addition, the control of bromate formation and its economy is evaluated, and its operating characteristics and current application scope are summarized, which has a practical reference value for the follow-up in-depth study of the O3/UV process.

The ozone/peroxymonosulfate (O3/PMS) system has attracted widespread attention from researchers owing to its ability to produce hydroxyl radicals (•OH) and sulfate radicals (SO4•−) simultaneously. The existing research has shown that the O3/PMS system significantly degrades refinery trace organic compounds (TrOCs) in highly concentrated organic wastewater. However, there is still a lack of systematic understanding of the O3/PMS system, which has created a significant loophole in its application in the treatment of highly concentrated organic wastewater. Hence, this paper reviewed the specific degradation effect, toxicity change, reaction mechanism, various influencing factors and the cause of oxidation byproducts (OBPs) of various TrOCs when the O3/PMS system is applied to the degradation of highly concentrated organic wastewater. In addition, the effects of different reaction conditions on the O3/PMS system were comprehensively evaluated. Furthermore, given the limited understanding of the O3/PMS system in the degradation of TrOCs and the formation of OBPs, an outlook on potential future research was presented. Finally, this paper comprehensively evaluated the degradation of TrOCs in highly concentrated organic wastewater by the O3/PMS system, filling the gaps in scale research, operation cost, sustainability and overall feasibility.

In recent years, due to the abuse of pharmaceuticals and personal care products (PPCPs), many refractory trace organic compounds (TrOCs) have been transferred into natural water bodies, posing significant challenges to the water environment. On the other hand, advanced oxidation processes (AOPs) are cleaner and more efficient than traditional biochemical degradation processes. Among them, the combined ozone/persulfate advanced oxidation process (O3/PMS) based on sulfate radicals (SO4•−) and hydroxyl radicals (•OH) has developed rapidly in recent years. Thus, this paper summarised the reaction mechanism of O3/PMS and analysed its research and application progress in drinking water treatment. In addition, the process’s operation characteristics and current application scope were discussed, and the generation ways and inhibition methods of bromate and halogenates, by-products in the oxidation process, were summarised, which had a specific reference value for further research on O3/PMS process.

Antibiotics are a new class of organic compounds that have antibacterial and anti-inflammatory effects in the clinic, but their widespread use has serious adverse effects on the natural water environment. Sulfadiazine (SDZ) is a typical kind of antibiotic, and the treatment effect of the traditional biochemical degradation process has not been ideal. Thus, in order to find a more efficient and clean degradation method, we investigated the degradation effect of ozone/persulfate (O3/PMS) advanced oxidation process (AOPs) on SDZ in prepared water and natural water for the first time and compared it with the experimental results of ozone (O3) and ozone/ultraviolet (O3/UV) methods. The experimental results showed that when the initial mass concentration of O3 was 3 mg/L, the initial mass concentration of SDZ was 10 mg/L, the temperature was 25 °C, the pH was 6.8 ± 0.1, the Kobs of O3/PMS was 0.2497 min−1, and the Kobs values of O3 and O3/UV were 0.1242 and 0.1328 min−1, respectively. The time required for O3/PMS to degrade SDZ below the detection limit (0.01 mg/L) was about 7 min shorter than that of O3 and O3/UV. It was found that in O3/PMS, the increase in the initial mass concentration of SDZ inhibited its degradation, and the increase in the initial mass concentration of ozone increased the degradation rate of sulfadiazine. The degradation process conformed to the pseudo-first-order reaction kinetic equation. O3/PMS was suitable for weak alkaline environments. When pH was 9, the concentration of free radicals was the highest. Excessive alkalinity led to mutual quenching of free radicals and reduced the degradation rate. The mineralization effect of O3/PMS was slightly worse than that of the O3/UV process, but O3/PMS effectively degraded SDZ and fluorescent substances dissolved in water, with good prospects in practical engineering applications.

Pipeline transportation has become an effective way to transport sludge from wastewater treatment plants due to its high transportation efficiency, low operating cost, and low environmental pollution. Before designing and optimizing the sludge-conveying pipeline, it is first necessary to analyze the rheological properties of the sludge. In this paper, activated sludge with varying volume concentrations (Cw) of 2.38%, 3.94%, and 5.39% was used as the research object. Under three temperature (T) conditions of 293 K, 298 K, and 303 K, the sludge concentration and temperature were investigated, and based on the results, a rheological model of activated sludge was established. The experimental results indicated that the upward and downward paths of the shear stress change curve were generally similar but did not overlap, and a hysteresis loop was formed between the two due to the characteristics of sludge shear thinning. The limiting viscosity of sludge with different concentrations increased with the increase in sludge concentration. This phenomenon was caused by the differences in the internal flocculent network structure of sludge with different concentrations and the different fluid flow effects. At different shear rates, the shear stress and sludge viscosity in the experiment decreased with the increase in temperature. The stability of the test sludge was weakened with the increase in temperature. Additionally, the viscosity of sludge decreased with the increase in shear rate and then stabilized, exhibiting shear thinning characteristics. The above rheological properties were described using the Bingham and Herschel–Bulkley models.